A reaction proceeds in two elementary steps with the energetics listed below…

CHEMISTRY · Subjective · A Level · Chemistry · Energetics · Energetics

Problem

A reaction proceeds in two elementary steps with the energetics listed below (energies are given relative to the reactants, whose potential energy is defined as 0 kJ). Step 1: ΔH1=+25 kJ\Delta H_{1} = +25\,\text{kJ} Ea1=60 kJE_{a_1} = 60\,\text{kJ} Step 2: ΔH2=−40 kJ\Delta H_{2} = -40\,\text{kJ} Ea2=50 kJE_{a_2} = 50\,\text{kJ} Calculate the overall enthalpy change, ΔHrxn\Delta H_{\text{rxn}} (in kJ), for the reaction.

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